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SEBGL - ST4
GUIDELINES
ON
LONG FIRST MAINTENANCE PERIOD
CORROSION PROTECTION SYSTEMS
FOR STRUCTURAL STEELWORK
A COST COMPARISON
Structural Engineering Branch, ArchSD Page 1 of 28 19 - 1 -Page 1of 28
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STRUCTURAL ENGINEERING BRANCH
ARCHITECTURAL SERVICES DEPARTMENT
January 2009 (Revised)
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Content
Content Page
1. Introduction . 3
2. Classification of Environment ... 3
3. Life of Coating . 4
4. Choices for Long First Maintenance Systems .. 5
5. Cost Comparison between Type C or D painting System and Hot-Dip Galvanizing
Systems (including Type F Painting System) 6
6. Recommendation .10
7. References 11
Appendix Detailed Cost Comparison for Steel Sections of Blast-Cleaning Followed by
Type C or D Painting System and Hot-Dip Galvanizing Followed by Type F
Painting System
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1. Introduction
The protection of structural steelwork against corrosion can be achieved by many
methods. The selection of a protective system, however, involves qualitative
judgement on the relative importance of many factors that can vary widely according
to the type of structure, its function, its general location, its immediate environment,
and the required life to first maintenance. Cost, needless to say, also plays an
important part in the selection. BS EN ISO 12944 andBS EN ISO 14713 (partially
superseding BS 5493: 1977) has provided guidelines on the choices. The ArchSD
General Specification for Building 2007(the G.SS. for Building (2007)) Table 15.7
also suggests some systems for selection. In the selection of a protective system, the
specifier should consider the environments of the steel structure and the
durability required of the painting system for the first major maintenance of the
painting.
2. Classification of Environment
According to BS EN ISO 12944-2, atmospheric environments are classified as six
atmospheric-corrosivity categories (Table 1):
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Table 1 Classification of Corrosivity Category
Corrosivity
category
Degree of
corrosivity
Examples of typical environments
Exterior Interior
C1 very low----
Heated buildings with
clean atmosphere, e.g.
offices, schools
C2 low
Atmospheres with low
level of pollution.
Mostly rural areas
Unheated buildings where
condensation may occur,
e.g. depots, sports halls
C3 medium
Urban and industrial
atmospheres, moderate
sulfur dioxide
pollution. Coastal areas
with low salinity
Production rooms with
high humidity and some
air pollution, e.g. food-
processing plants,
laundries
C4 high
Industrial areas and
coastal areas with
moderate salinity
Chemical plants,
swimming pools, coastal
ship and boatyards
C5-Ivery high
(industrial)
Industrial areas with
high humidity and
aggressive atmosphere
Buildings or areas with
almost permanent
condensation and with
high pollution
C5-M very high(marine)
Coastal and offshoreareas with high salinity
Buildings or areas with
almost permanentcondensation and with
high pollution
(Source: Adapted fromBS EN ISO12944 2andBS EN ISO 14713)
3. Life of Coating
According to BS EN ISO 12944 and BS EN ISO 14713ISO 12944, the life or
durability of coating is considered as the time which can elapse before the first
major or general maintenance of the coating becomes necessary, or is more
commonly known as the Life to First Maintenance. Experience shows that Type A
painting to Table 15.7 of the G.S. for Building (2007), the life of the painting can
achieve about 2 to 3 years in the environment of Hong Kong, whereas it will be about
5 years for Type B painting.
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For Type C, D painting systems to Table 15.7 of the for Building (2007) and hot-dip
galvanizing without painting system, Type C, D painting systems and hot-dip
galvanizing with or without painting (Type F) are expected to have a long period of
first maintenance period for about 10 to 15 years even for C3 or C4 environment in
Hong Kong.Corus (2004) predicted the Life to First Maintenance based on their own
practical experience and the corrosion rates given in BS EN ISO 12944 and BS EN
ISO 14713, and their prediction is shown in Table 2:
Table 2 Anticipated Life of First Maintenance
with Different Corrosion Protection Systems
Corrosion Protection Systems Corrosivity category Life to First Maintenance
Type C Painting SystemC3 20 years
C4 15 years
Type D Painting SystemC3 25 years
C4 15-20 years
Hot-dip galvanizing (min
85m) without painting
system
C3 40 years
C4 30 years
( BS EN ISO 1461 specifies the standard hot-dip galvanized coating to be 85m
for steel 6mm thick or more, and that thinner steel has thinner coatings.)
However, it is considered that the prediction by Corus (2004) is generally on the
high side, and our experience notes that Type C, D painting systems and hot-dip
galvanizing with or without Type F painting system are expected to have a first
maintenance period for about 10 to 15 years for C3 or C4 environment in Hong Kong.
According toBS EN ISO 12944 andBS EN ISO 14713, the life or durability of
coating is considered as the time which can elapse before the first major or general
maintenance of the coating becomes necessary, or is more commonly known as the
Life to First Maintenance. Experience shows that Type A painting to Table 15.7 of
the GS for Building (2007), the life of the painting can achieve about 2 to 3 years in
the environment of Hong Kong, whereas it will be about 5 years for Type B painting.
And our experience notes that Type C, D painting systems and hot-dip galvanizing
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with or without Type F painting system are expected to have a first maintenance
period for about 15 years for C3 or C4 environment in Hong Kong.
4. Choices for Long First Maintenance Systems
4.1 For the Long First Maintenance Systems (i.e. 10-about 15 years), if in accordance
with the G.S. for Building (2007), the choice in effect is between blast-cleaning
followed by Type C (or D) painting systems and hot-dip galvanizing (with or
withoutor Type F orand G painting systems). The factors that have to be taken into
account for a choice include :-
(a) cCost.
(b) eEaste of control for quality.
(c) pPerformance.
4.2 From experience of the past ArchSD projects, the hot-dip galvanizing is generally
easier to be used as long as the galvanizer is a well-established one; the difficult areas
are only at fasteners and welded joints. Though hot-dip galvanized bolts and nuts are
now readily available in Hong Kong, electro-plated fasteners are sometimes
mistakenly used. It should be noted that electroplated bolts can corrode quickly within
a few years. Therefore, hot-dip galvanized fasteners should always be used for long
first maintenance protective system. PSE should brief the site staff to check the
fasteners delivered to site.
4.3 Type C or D painting systems in Table 15.7 of the GS for Building (2007) are in line
with the painting systems A3.11, A4.14 or A4.15 ofBS EN ISO 12944, which can
achieve 10 toabout 15 years first maintenance period for C3 or C4 environment.
These systems are also in line with recommendation of the superseded BS 5493 in
that systems SK3 and SL6 were suggested to provide for exterior exposed polluted
inland.
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4.4 However, Type C (or D) painting systems, since it requires labour for blast cleaning
and painting, demands more supervision and more control on workmanship. Further
discussion on the choice of the corrosion protection system for different first
maintenance can be found in SEB Guidelines ST3: Notes on Protective Coating of
Steel Structures Against Corrosion.
4.5 The following sectionparagraph will compare the cost between blast-cleaning
followed by Type C or to D painting systems and hot-dip galvanizing (with or
withoutincluding Type F painting system).
5. Cost Comparison between Type C toor D Painting Systems and Hot-Dip
Galvanizing Systems (including Type F Painting System)
5.1 In 1994, this set of Guidelines was first issued to compare the cost of providing
corrosion protection between the then Type C painting system (now Type C and D
painting systems) and hot-dip galvanizing (including Type F painting system). At
that time, extensive surveys of the paint manufacturers and/or suppliers had been
conducted to obtain the then market price for the above corrosion protection systems.
It was found that the cost blast-cleaning followed by Types C or D painting system
was $120/m2, whilst the cost of galvanizing was $4/kg plus the cost of Type F
painting system at $32/m2. With such data, the Guidelines in 1994 concluded that
hot-dip galvanizing (including Type F painting system) became more cost-effective
solution for steel sections with surface area greater than 33m2 per tonne.
5.1 Painting Systems
Type C to D painting systems in Table 15.7 of the G.S. for Building (2007) are in line
with the painting systems A3.11, A4.14 or A4.15 ofBS EN ISO 12944, which can
achieve 10 to 15 years first maintenance period for C3 or C4 environment. These
systems are also in line with recommendation of partially superseded BS 5493 in
that systems SK3 and SL6 were suggested to provide for exterior exposed polluted
inland.
5.22 Unit Cost of Painting
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In 1994, this Guidelines was first issued to compare the cost of providing corrosion
protection between the then Type C painting system (now Type C to D painting
systems) and hot-dip galvanizing (including Type F painting system). At that time,
extensive surveys of the paint manufacturers and/or suppliers had been conducted to
obtain the then market price for the above corrosion protection systems. It was found
that the cost of Types C to D painting system was $120/m2, whilst the cost of
galvanizing was $4/kg plus the cost of Type F painting system at $32/m2. With such
data, the Guidelines in 1994 concluded that hot-dip galvanizing (including Type F
painting system became more cost-effective solution for steel sections with surface
area greater than 33m2 per tonne.
5.2.2 For the purpose of this revision, this Guidelinesset of Guidelines has conducted
another survey in November 2008 on the current market price for the above items.
Four suppliers and/or contractors have been consulted, and the current prices for
blast-cleaning followed by Type C or D painting system are as follows:
Grit blasting to Sa 2 $36.5/m
Cost of paint (including wastage) $84.0/m
Labour $35.0/m
Allow for 15% profit $14.5/m
___________
Total $170/m
5.33 Cost of Hot-Dip Galvanizing
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The market price for hot-dip galvanizing to BS EN ISO 1461 is $3.0/kg
($3000/tonne).
5.44 Cost of Painting to Galvanized Steel
Type F painting system surface involves applying British Rail T-Wash to the
galvanized surface followed by two coats of finishing paint with a dry film thickness
of 80 m. The market price of such painting system is:
Cost : T-Wash + Painting = $38.5/m
Labour = $35.0/m
Profit = $6.5/m
___________
Total $80/m
5.55 Comparison of Cost of Protection for Long Life
5.5.1 The cost of comparison between blast-cleaning followed by Type C orto D painting
systems and hot-dip galvanizing (including Type F painting system) is attached in
Appendix. The results are summarised in Figures 1.
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SurfaceArea = 18 SurfaceArea = 33
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Figure 1 Cost Comparison between Painting and
Hot-Dip Galvanizing
5.5.2 Figures 1 shows that the cost of protection differs depending on the surface area per
unit tonne of section. For heavy section, i.e. less surface areas per tonne, less painting
will be required thus the painting cost is less. On the other handHowever, , the costof galvanizing is relatively constant irrespective the less surface area.
Two break-even points can therefore be found at surface area of 18m/tonne and 33
m/tonne. The two breakeven points indicate that:
(i) for section where the surface area is more than 18 m/tonne, blast-
cleaning followed by Type C or D painting system is more cost
effective than hot-dip galvanizing (without any painting system); and
(ii) for section where the surface area is more than 33 m/tonne, It is found
that blast-cleaning followed by Type C or D painting system is more
cost effective than hot-dip galvanizing (including Type F painting
system). in general except for light section where the surface area is
more than 33 m/tonne.
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5.5.3 The following examples for UC, UB, channel, angle, CHS, SHS and RHS are chosen
for comparison. They have been chosen as representatives for light-, medium- and
heavy-weight members of ..each section.
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For example :-
Area (m ) /tonne) Paint ing - Galva nizing Gal+
Painting
- Gal. +
/Tonne ing nize UC
($ Per tonne of Section)
152 x 152 x 37 kg/m 24.70 4199 3000 4976
254x254x89 kg/m 16.90 2873 3000 4352
305x305x158 kg/m 11.60 1972 3000 3928Pating
UB ($ Per tonne of Section)
203 x 133 x 3025 kg/m 36.400.80 61885236 3000 5912464
356 x 127 x 39 kg/m 30.20 5134 3000 5416
457 x 152 x 82 kg/m 18.40 3128 3000 4472
UC
152 x 152 x 37 kg/m 24.70 4199 3000 4976
254x254x89 kg/m 16.90 2873 3000 4352
305x305x158 kg/m 11.60 1972 3000 3928
Channel s
102 x 51 x 10.42 kg/m 36.30 6171 3000 5904
127 x 64 x 14.90 kg/m 32.00 5440 3000 5760
152 x 89 x 23.84 kg/m 26.00 4420 3000 5080
Angle s
65 x 65 x 4 mm 67.36 11451 3000 8389
1200 x 1200 x 108 mm 34.3627.62 58414695 3000 57845209
225 x 225 x 15 mm 18.15 3085 3000 4452
CHS
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26.9x3.2mm 35.5 6035 3000 584088.9x3.2 mm 32.40 5508 3000 5592
88.9x3.2 mm 32.40 5508 3000 5592193.7x5.0 mm 20.6 3502 3000 4648
457x8.0mm 12.8 2176 3000 4024
SHS
90x90x3.6kg/m 36.30 6171 3000 5904
140x140x5.0 kg/m 26.00 4420 3000 5080
300x300x6.3 kg/m 20.40 3468 3000 4632
RHS
100x50x3.0mm 43.50 7395 3000 6480
200x100x5.0 mm 26.00 4420 3000 5080
450x250x8.0mm 16.20 2754 3000 4296
6. Recommendations
6.1 For 10-about 115 years first maintenance period, it is recommended that :-
Use hot-dip galvanize if surface area 18m per tonne of Section.
(a). If no painting to the finished galvanized surfaces is required and
without too much touch up to welded areas is required, use hot-dip galvanizing
if surface area 18m per tonne of section.
(b). If aesthetic is an important consideration and that painting is required, use Type
C or D painting system if surface area Use blast-cleaning followed by Type C
painting or equivalent if surface area < 33 m per tonne of sSection, and
hot-dip galvanizing +followed by Type F painting system when surface area >
33 m per tonne of section.
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If no painting to the finished galvanized surfaces is required, use hot-dip
galvanizing if surface area 18m per tonne of section.
6.2 With this rule, most structural framework using universal beams and columns is to be
protected by painting, and hot-dip galvanizing is for lightweight framework or lattice
girders assembled by angles or channels or where additional painting is not required
to the finished galvanized surfaces. For longer period of protection (e.g. 20 years or
more), hot-dip galvanizing to more than 140 micron or sprayed zinc will be required;
on thisBS EN ISO 12944 andBS EN ISO 14713 provides more information.
6.3 However, the above rule is not rigid and consideration should be given to the
particular situation of each project, e.g. type of structure, function, general and
immediate environment and the staff requirement for supervision.
In the earlier section, it has been stated that the hot-dip galvanizing is generally
easier to be used as long as the galvanizer is a well-established one; the difficult areas
are only at fasteners and welded joints. Hence, if the cost of hot-dip galvanizing is
marginally (say 10%) higher than the cost of blast-cleaning followed by Type C or D
panting system, PSE may prefer to choose hot-dip galvanizing instead. PSE should
also make judgement on the combination of the sections used with different m2/tonne,
eg. in the case of trusses with combination of I-beams, angles and channels.
7. References
British Standard Institution (1977), Code of Practice for Protective Coating of Ironand Steel Structures Against Corrosion (London: BSI).
British Standard Institution (1998), BS EN ISO 12944-1: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 1: Part 1:
General Introduction (London:, BSI).
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British Standard Institution (1998), BS EN ISO 12944-2: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 2:
Classification of Environments (London:, BSI).
British Standard Institution (1998), BS EN ISO 12944-3: Paints and Varnishes -
Corrosion Protection of Steel Structures by Protective Paint Systems - Part 3: DesignConsiderations (London:, BSI).
British Standard Institution (1998), BS EN ISO 12944-4: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 4: Types
of Surface and Surface Preparation (London:, BSI).
British Standard Institution (2007), BS EN ISO 12944-5: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 5:
Protective Paint Systems (London:, BSI).
British Standard Institution (1998), BS EN ISO 12944-6: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 6:
Laboratory Performance Test Methods (London:, BSI).
British Standard Institution (1998), BS EN ISO 12944-7: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 7:
Execution and Supervision of Paintwork(London:, BSI).
British Standard Institution (1998), BS ENISO 12944-8: Paints and Varnishes -Corrosion Protection of Steel Structures by Protective Paint Systems - Part 8:
Development of Specifications for New Work and Maintenance (London:, BSI).
British Standard Institution (1999), BS EN ISO 1461: Hot Dip Galvanized Coatingson Fabricated Iron and Steel Articles Specification (London: BSI).Corus (2004), A Corrosion Protection Guide for Steelwork Exposed to Atmospheric
Environments (Scunthorpe: Corus Construction & Industrial) (Available:
http://www.corusconstruction.com , Accessed: 2 January 2009).
British Standard Institution (1999),BS EN ISO14713: Protection Against Corrosionof Iron and Steel in Structures Zinc and Aluminium Coatings - Guidelines (London:BSI).
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Appendix
Detailed Cost Comparison for Steel Sections of Blast-Cleaning Followed by Type C
or D Painting System and Hot-Dip Galvanizing Followed by Type F Painting System
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UC
SectionSurface
Area /tonneCost Comparison of Different Protection ($ / ton of section)
mm (m2 /ton) Painting Galvanize only Gal+Painting
356 x 406 x634
3.98 HK$676.60 HK$3,000.0 HK$3,318.40 356 x 406 x551
4.49 HK$763.30 HK$3,000.0 HK$3,359.20 356 x 406 x467
5.19 HK$882.30 HK$3,000.0 HK$3,415.20 356 x 406 x393
6.05 HK$1,028.50 HK$1,077.07 HK$3,000.0 HK$3,484.00 HK$3,506.86
356 x 406 x340
6.90 HK$1,173.00 HK$3,000.0 HK$3,552.00 356 x 406 x287
8.05 HK$1,368.50 HK$3,000.0 HK$3,644.00 356 x 406 x235
9.69 HK$1,647.30 HK$3,000.0 HK$3,775.20 356 x 368 x202
10.80 HK$1,836.00 HK$3,000.0 HK$3,864.00 356 x 368 x177
12.30 HK$2,091.00 HK$3,000.0 HK$3,984.00 356 x 368 x153
14.10 HK$2,397.00 HK$2,286.50 HK$3,000.0 HK$4,128.00 HK$4,076.00
356 x 368 x129
16.60 HK$2,822.00 HK$3,000.0 HK$4,328.00 305 x 305 x283
6.86 HK$1,166.20 HK$3,000.0 HK$3,548.80 305 x 305 x240
7.94 HK$1,349.80 HK$3,000.0 HK$3,635.20 305 x 305 x198
9.46 HK$1,608.20 HK$3,000.0 HK$3,756.80 305 x 305 x158
11.60 HK$1,972.00 HK$2,014.74 HK$3,000.0 HK$3,928.00 HK$3,948.11
305 x 305 x137
13.30 HK$2,261.00 HK$3,000.0 HK$4,064.00 305 x 305 x118
15.30 HK$2,601.00 HK$3,000.0 HK$4,224.00 305 x 305 x97
18.50 HK$3,145.00 HK$3,000.0 HK$4,480.00 254 x 254 x167
9.45 HK$1,606.50 HK$3,000.0 HK$3,756.00 254 x 254 x132
11.70 HK$1,989.00 HK$3,000.0 HK$3,936.00 254 x 254 x107
14.20 HK$2,414.00 HK$2,470.10 HK$3,000.0 HK$4,136.00 HK$4,162.40
254 x 254 x89
16.90 HK$2,873.00 HK$3,000.0 HK$4,352.00 254 x 254 x73
20.40 HK$3,468.00 HK$3,000.0 HK$4,632.00 203 x 203 x86
14.40 HK$2,448.00 HK$3,000.0 HK$4,152.00 203 x 203 x71
17.20 HK$2,924.00 HK$3,000.0 HK$4,376.00 203 x 203 x60
20.10 HK$3,417.00 HK$3,417.00 HK$3,000.0 HK$4,608.00 HK$4,608.00
203 x 203 x52
23.00 HK$3,910.00 HK$3,000.0 HK$4,840.00 203 x 203 x46
25.80 HK$4,386.00 HK$3,000.0 HK$5,064.00 152 x 152 x37
24.70 HK$4,199.00 HK$3,000.0 HK$4,976.00 152 x 152 x30
30.00 HK$5,100.00 HK$5,292.67 HK$3,000.0 HK$5,400.00 HK$5,490.67
152 x 152 x23
38.70 HK$6,579.00 HK$3,000.0 HK$6,096.00
Notes: Cost of blast-cleaning followed by Type C or D painting system is always less than 110% of the costof hot-dip galvanizing followed by Type F painting system,..
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Guidelines on Long First Maintenance Period CorrosionProtection Systems
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Issue No./Revision No. : 1/1 Issue/Revision Date : January 2009
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UB
SectionSurface
Area /tonneCost Comparison of Different Protection ($ / ton of section)
mm (m2 /ton) Painting Galvanize only Gal+Painting
914 x 419 x388
8.87 HK$1,507.90 HK$3,000.0 HK$3,709.60 914 x 419 x343
9.95 HK$1,691.50 HK$3,000.0 HK$3,796.00 914 x 305 x289
10.40 HK$1,768.00 HK$3,000.0 HK$3,832.00 914 x 305 x253
11.80 HK$2,006.00 HK$1,955.57 HK$3,000.0 HK$3,944.00 HK$3,920.27
914 x 305 x224
13.30 HK$2,261.00 HK$3,000.0 HK$4,064.00 914 x 305 x201
14.70 HK$2,499.00 HK$3,000.0 HK$4,176.00 838 x 292 x226
12.40 HK$2,108.00 HK$3,000.0 HK$3,992.00 838 x 292 x194
14.40 HK$2,448.00 HK$2,414.00 HK$3,000.0 HK$4,152.00 HK$4,136.00
838 x 292 x176
15.80 HK$2,686.00 HK$3,000.0 HK$4,264.00 762 x 267 x197
13.00 HK$2,210.00 HK$3,000.0 HK$4,040.00 762 x 267 x173
14.60 HK$2,482.00 HK$3,000.0 HK$4,168.00 762 x 267 x147
17.10 HK$2,907.00 HK$2,694.50 HK$3,000.0 HK$4,368.00 HK$4,268.00
762 x 267 x134
18.70 HK$3,179.00 HK$3,000.0 HK$4,496.00 686 x 254 x170
13.80 HK$2,346.00 HK$3,000.0 HK$4,104.00 686 x 254 x152
15.40 HK$2,618.00 HK$3,000.0 HK$4,232.00 686 x 254 x140
16.60 HK$2,822.00 HK$2,732.75 HK$3,000.0 HK$4,328.00 HK$4,286.00
686 x 254 x125
18.50 HK$3,145.00 HK$3,000.0 HK$4,480.00 610 x 305 x238
10.30 HK$1,751.00 HK$3,000.0 HK$3,824.00 610 x 305 x179
13.50 HK$2,295.00 HK$2,255.33 HK$3,000.0 HK$4,080.00 HK$4,061.33
610 x 305 x149
16.00 HK$2,720.00 HK$3,000.0 HK$4,280.00 610 x 229 x140
15.10 HK$2,567.00 HK$3,000.0 HK$4,208.00 610 x 229 x125
16.70 HK$2,839.00 HK$3,000.0 HK$4,336.00 610 x 229 x113
18.40 HK$3,128.00 HK$3,004.75 HK$3,000.0 HK$4,472.00 HK$4,414.00
610 x 229 x101
20.50 HK$3,485.00 HK$3,000.0 HK$4,640.00 533 x 210 x122
15.50 HK$2,635.00 HK$3,000.0 HK$4,240.00 533 x 210 x109
17.20 HK$2,924.00 HK$3,000.0 HK$4,376.00 533 x 210 x101
18.50 HK$3,145.00 HK$3,192.60 HK$3,000.0 HK$4,480.00 HK$4,502.40
533 x 210 x92
20.20 HK$3,434.00 HK$3,000.0 HK$4,616.00 533 x 210 x82
22.50 HK$3,825.00 HK$3,000.0 HK$4,800.00 457 x 191 x98
16.90 HK$2,873.00 HK$3,000.0 HK$4,352.00 457 x 191 x89
18.50 HK$3,145.00 HK$3,000.0 HK$4,480.00 457 x 191 x82
20.10 HK$3,417.00 HK$3,464.60 HK$3,000.0 HK$4,608.00 HK$4,630.40
457 x 191 x74
22.10 HK$3,757.00 HK$3,000.0 HK$4,768.00
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Guidelines on Long First Maintenance Period CorrosionProtection Systems
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457 x 191 x67
24.30 HK$4,131.00 HK$3,000.0 HK$4,944.00 457 x 152 x82
18.40 HK$3,128.00 HK$3,000.0 HK$4,472.00 457 x 152 x74
20.30 HK$3,451.00 HK$3,000.0 HK$4,624.00 457 x 152 x67
22.30 HK$3,791.00 HK$3,879.40 HK$3,000.0 HK$4,784.00 HK$4,825.60
457 x 152 x60
24.90 HK$4,233.00 HK$3,000.0 HK$4,992.00 457 x 152 x52
28.20 HK$4,794.00 HK$3,000.0 HK$5,256.00
Structural Engineering Branch, ArchSD Page 22 of 28 1 9 - 22 -Page22 of 28
File code : ST-4.doc
Guidelines on Long First Maintenance Period CorrosionProtection Systems
CTW/MKL/IL/
Issue No./Revision No. : 1/1 Issue/Revision Date : January 2009
Cost of painting > 110% of Cost of gal + painting
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UB (contd)
SectionSurface
Area /tonne
Cost Comparison of Different Protection ($ / ton of section)
mm (m2 /ton) PaintingGalvanize
onlyGal+Painting
406 x 178 x74
20.30 HK$3,451.00 HK$3,000.0 HK$4,624.00 406 x 178 x67
22.30 HK$3,791.00 HK$3,000.0 HK$4,784.00 406 x 178 x60
24.80 HK$4,216.00 HK$4,029.00 HK$3,000.0 HK$4,984.00 HK$4,896.00
406 x 178 x54
27.40 HK$4,658.00 HK$3,000.0 HK$5,192.00 406 x 140 x46
29.20 HK$4,964.00 HK$3,000.0 HK$5,336.00 406 x 140 x39
34.20 HK$5,814.00 HK$5,389.00 HK$3,000.0 HK$5,736.00 HK$5,536.00
356 x 171 x
6720.60 HK$3,502.00 HK$3,000.0 HK$4,648.00
356 x 171 x57
24.10 HK$4,097.00 HK$3,000.0 HK$4,928.00 356 x 171 x51
26.70 HK$4,539.00 HK$4,734.50 HK$3,000.0 HK$5,136.00 HK$5,228.00
356 x 171 x45
30.10 HK$5,117.00 HK$3,000.0 HK$5,408.00 356 x 127 x39
30.20 HK$5,134.00 HK$3,000.0 HK$5,416.00 356 x 127 x33
35.40 HK$6,018.00 HK$3,000.0 HK$5,832.00 305 x 165 x54
23.30 HK$3,961.00 HK$3,000.0 HK$4,864.00 305 x 165 x46
27.10 HK$4,607.00 HK$4,601.33 HK$3,000.0 HK$5,168.00 HK$5,165.33
305 x 165 x
4030.80 HK$5,236.00 HK$3,000.0 HK$5,464.00
305 x 127 x48
22.70 HK$3,859.00 HK$3,000.0 HK$4,816.00 305 x 127 x42
25.80 HK$4,386.00 HK$4,391.67 HK$3,000.0 HK$5,064.00 HK$5,066.67
305 x 127 x37
29.00 HK$4,930.00 HK$3,000.0 HK$5,320.00 305 x 102 x33
30.80 HK$5,236.00 HK$3,000.0 HK$5,464.00 305 x 102 x28
35.40 HK$6,018.00 HK$6,018.00 HK$3,000.0 HK$5,832.00 HK$5,832.00
305 x 102 x25
40.00 HK$6,800.00 HK$3,000.0 HK$6,200.00 254 x 146 x43
25.10 HK$4,267.00 HK$3,000.0 HK$5,008.00 254 x 146 x
37 29.00 HK$4,930.00 HK$5,003.67 HK$3,000.0 HK$5,320.00 HK$5,354.67254 x 146 x31
34.20 HK$5,814.00 HK$3,000.0 HK$5,736.00 254 x 102 x28
31.90 HK$5,423.00 HK$3,000.0 HK$5,552.00 254 x 102 x25
35.60 HK$6,052.00 HK$6,120.00 HK$3,000.0 HK$5,848.00 HK$5,880.00
254 x 102 x22
40.50 HK$6,885.00 HK$3,000.0 HK$6,240.00 203 x 133 x30
30.80 HK$5,236.00 HK$3,000.0 HK$5,464.00 203 x 133 x25
36.40 HK$6,188.00 HK$5,712.00 HK$3,000.0 HK$5,912.00 HK$5,688.00
203 x 102 x23
34.20 HK$5,814.00 HK$3,000.0 HK$5,736.00 178 x 102 x19 38.80 HK$6,596.00 HK$3,000.0 HK$6,104.00 152 x 89 x 16 39.80 HK$6,766.00 HK$3,000.0 HK$6,184.00 Structural Engineering Branch, ArchSD Page 23 of 28 1 9 - 23 -Page
23 of 28File code : ST-4.doc
Guidelines on Long First Maintenance Period CorrosionProtection Systems
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127 x 76 x 13 41.30 HK$7,021.00 HK$3,000.0 HK$6,304.00 203 x 133 x30
30.80 HK$5,236.00 HK$3,000.0 HK$5,464.00 203 x 133 x25
36.40 HK$6,188.00 HK$5,712.00 HK$3,000.0 HK$5,912.00 HK$5,688.00
203 x 102 x23
34.20 HK$5,814.00 HK$3,000.0 HK$5,736.00 178 x 102 x19 38.80 HK$6,596.00 HK$3,000.0 HK$6,104.00 152 x 89 x 16 39.80 HK$6,766.00 HK$3,000.0 HK$6,184.00 127 x 76 x 13 41.30 HK$7,021.00 HK$3,000.0 HK$6,304.00
UC
SectionSurface
Area /tonneCost Comparison of Different Protection ($ / ton of section)
mm (m2 /ton) Painting Galvanize only Gal+Painting
356 x 406 x634
3.98 HK$676.60 HK$3,000.0 HK$3,318.40 356 x 406 x551
4.49 HK$763.30 HK$3,000.0 HK$3,359.20 356 x 406 x467
5.19 HK$882.30 HK$3,000.0 HK$3,415.20 356 x 406 x393
6.05 HK$1,028.50 HK$1,077.07 HK$3,000.0 HK$3,484.00 HK$3,506.86
356 x 406 x340
6.90 HK$1,173.00 HK$3,000.0 HK$3,552.00 356 x 406 x287 8.05 HK$1,368.50 HK$3,000.0 HK$3,644.00 356 x 406 x235
9.69 HK$1,647.30 HK$3,000.0 HK$3,775.20 356 x 368 x202
10.80 HK$1,836.00 HK$3,000.0 HK$3,864.00 356 x 368 x177
12.30 HK$2,091.00 HK$3,000.0 HK$3,984.00 356 x 368 x153
14.10 HK$2,397.00 HK$2,286.50 HK$3,000.0 HK$4,128.00 HK$4,076.00
356 x 368 x129
16.60 HK$2,822.00 HK$3,000.0 HK$4,328.00 305 x 305 x283
6.86 HK$1,166.20 HK$3,000.0 HK$3,548.80 305 x 305 x240
7.94 HK$1,349.80 HK$3,000.0 HK$3,635.20 305 x 305 x198 9.46 HK$1,608.20 HK$3,000.0 HK$3,756.80 305 x 305 x 11.60 HK$1,972.00 HK$2,014.74 HK$3,000.0 HK$3,928.00 HK$3,948.11
Structural Engineering Branch, ArchSD Page 24 of 28 1 9 - 24 -Page24 of 28
File code : ST-4.doc
Guidelines on Long First Maintenance Period CorrosionProtection Systems
CTW/MKL/IL/
Issue No./Revision No. : 1/1 Issue/Revision Date : January 2009
Cost of painting > 110% of Cost of gal + painting
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158
305 x 305 x137
13.30 HK$2,261.00 HK$3,000.0 HK$4,064.00 305 x 305 x118
15.30 HK$2,601.00 HK$3,000.0 HK$4,224.00 305 x 305 x97
18.50 HK$3,145.00 HK$3,000.0 HK$4,480.00 254 x 254 x167 9.45 HK$1,606.50 HK$3,000.0 HK$3,756.00 254 x 254 x132
11.70 HK$1,989.00 HK$3,000.0 HK$3,936.00 254 x 254 x107
14.20 HK$2,414.00 HK$2,470.10 HK$3,000.0 HK$4,136.00 HK$4,162.40
254 x 254 x89
16.90 HK$2,873.00 HK$3,000.0 HK$4,352.00 254 x 254 x73
20.40 HK$3,468.00 HK$3,000.0 HK$4,632.00 203 x 203 x86
14.40 HK$2,448.00 HK$3,000.0 HK$4,152.00 203 x 203 x71
17.20 HK$2,924.00 HK$3,000.0 HK$4,376.00 203 x 203 x60
20.10 HK$3,417.00 HK$3,417.00 HK$3,000.0 HK$4,608.00 HK$4,608.00
203 x 203 x52 23.00 HK$3,910.00 HK$3,000.0 HK$4,840.00 203 x 203 x46
25.80 HK$4,386.00 HK$3,000.0 HK$5,064.00 152 x 152 x37
24.70 HK$4,199.00 HK$3,000.0 HK$4,976.00 152 x 152 x30
30.00 HK$5,100.00 HK$5,292.67 HK$3,000.0 HK$5,400.00 HK$5,490.67
152 x 152 x23
38.70 HK$6,579.00 HK$3,000.0 HK$6,096.00
Remarks: Cost of painting is always less than the cost of gal + painting in this case, and therefore use paintingas corrosion protection system for UC sections is recommended.
Structural Engineering Branch, ArchSD Page 25 of 28 1 9 - 25 -Page25 of 28
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Guidelines on Long First Maintenance Period CorrosionProtection Systems
CTW/MKL/IL/
Issue No./Revision No. : 1/1 Issue/Revision Date : January 2009
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Channel
SectionSurface Area
/tonne
Cost Comparison of Different Protection ($ / ton of section)
mm (m2 /ton) Painting Galvanize only Gal+Painting
432x102 18.60 HK$3,162.00 HK$3,000.0 HK$4,488.00 381x102 20.30 HK$3,451.00 HK$3,000.0 HK$4,624.00 305x102 20.90 HK$3,553.00 HK$3,000.0 HK$4,672.00 305x89 22.10 HK$3,757.00 HK$3,000.0 HK$4,768.00 254x89 23.00 HK$3,910.00 HK$3,000.0 HK$4,840.00 254x76 27.40 HK$4,658.00 HK$3,000.0 HK$5,192.00 229x89 23.50 HK$3,995.00 HK$3,000.0 HK$4,880.00 229x76 27.80 HK$4,726.00 HK$3,000.0 HK$5,224.00 203x89 24.20 HK$4,114.00 HK$3,000.0 HK$4,936.00 203x76 28.30 HK$4,811.00 HK$3,000.0 HK$5,264.00 178x89 25.00 HK$4,250.00 HK$3,000.0 HK$5,000.00 178x76 30.00 HK$5,100.00 HK$3,000.0 HK$5,400.00 152x89 26.00 HK$4,420.00 HK$3,000.0 HK$5,080.00 152x76 32.20 HK$5,474.00 HK$3,000.0 HK$5,576.00 127x64 32.00 HK$5,440.00 HK$3,000.0 HK$5,560.00 102x51 36.30 HK$6,171.00 HK$3,000.0 HK$5,904.00 76x38 42.10 HK$7,157.00 HK$3,000.0 HK$6,368.00
Angle
SectionSurface Area
/tonneCost Comparison of Different Protection ($ / ton of section)
mm (m2 /ton) Painting Galvanize only Gal+Painting
400x400x21 11.25 HK$1,912.50 HK$3,000.0 HK$3,900.00 350x350x18 14.86 HK$2,526.20 HK$3,000.0 HK$4,188.80 300x300x18 14.06 HK$2,390.20 HK$3,000.0 HK$4,124.80 240x240x15 18.05 HK$3,068.50 HK$3,000.0 HK$4,444.00 225x225x15 18.15 HK$3,085.50 HK$3,000.0 HK$4,452.00 200x200x15 18.26 HK$3,104.20 HK$3,000.0 HK$4,460.80 165x165x10 26.83 HK$4,561.10 HK$3,000.0 HK$5,146.40 120x120x10 27.62 HK$4,695.40 HK$3,000.0 HK$5,209.60 115x115x8 34.07 HK$5,791.90 HK$3,000.0 HK$5,725.60 100x100x8 34.36 HK$5,841.20 HK$3,000.0 HK$5,748.80 90x90x6 45.00 HK$7,650.00 HK$3,000.0 HK$6,600.00 80x80x6 45.45 HK$7,726.50 HK$3,000.0 HK$6,636.00 65x65x4 67.36 HK$11,451.20 HK$3,000.0 HK$8,388.80 60x60x4 67.42 HK$11,461.40 HK$3,000.0 HK$8,393.60 50x50x4 68.97 HK$11,724.90 HK$3,000.0 HK$8,517.60
Structural Engineering Branch, ArchSD Page 26 of 28 1 9 - 26 -Page26 of 28
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Guidelines on Long First Maintenance Period CorrosionProtection Systems
CTW/MKL/IL/
Issue No./Revision No. : 1/1 Issue/Revision Date : January 2009
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CHS
SectionSurface
Area /tonneCost Comparison of Different Protection ($ / ton of section)
mm (m2 /ton) Painting Galvanize only Gal+Painting
508x8.0 12.7 HK$2,159.00 HK$3,000.0 HK$4,016.00 457.0x8.0 12.8 HK$2,176.00 HK$3,000.0 HK$4,024.00 406.4x6.3 16.2 HK$2,754.00 HK$3,000.0 HK$4,296.00 323.9x6.3 16.2 HK$2,754.00 HK$3,000.0 HK$4,296.00 273.0x5.0 20.4 HK$3,468.00 HK$3,000.0 HK$4,632.00 244.5x12 8.76 HK$1,489.20 HK$3,000.0 HK$3,700.80 219.1x5.0 20.5 HK$3,485.00 HK$3,000.0 HK$4,640.00 193.7x5.0 20.6 HK$3,502.00 HK$3,000.0 HK$4,648.00 168.3x5.0 20.6 HK$3,502.00 HK$3,000.0 HK$4,648.00 139.7x5.0 20.7 HK$3,519.00 HK$3,000.0 HK$4,656.00 114.3x3.2 32.1 HK$5,457.00 HK$3,000.0 HK$5,568.00 88.9x3.2 32.4 HK$5,508.00 HK$3,000.0 HK$5,592.00 76.1x3.2 32.6 HK$5,542.00 HK$3,000.0 HK$5,608.00 60.3x3.2 32.9 HK$5,593.00 HK$3,000.0 HK$5,632.00 18.3x3.2 33.6 HK$5,712.00 HK$3,000.0 HK$5,688.00 42.4x3.2 33.8 HK$5,746.00 HK$3,000.0 HK$5,704.00 26.9x3.2 35.5 HK$6,035.00 HK$3,000.0 HK$5,840.00
SHS
SectionSurface
Area /tonneCost Comparison of Different Protection ($ / ton of section)
mm (m2 /ton) Painting Galvanize only Gal+Painting
400x400x10.0 12.9 HK$2,193.00 HK$3,000.0 HK$4,032.00 350x350x8.0 16.2 HK$2,754.00 HK$3,000.0 HK$4,296.00 300x300x6.3 20.4 HK$3,468.00 HK$3,000.0 HK$4,632.00 250x250x6.3 20.5 HK$3,485.00 HK$3,000.0 HK$4,640.00 200x200x5.0 25.9 HK$4,403.00 HK$3,000.0 HK$5,072.00 180x180x6.3 20.7 HK$3,519.00 HK$3,000.0 HK$4,656.00 160x160x5.0 26 HK$4,420.00 HK$3,000.0 HK$5,080.00 150x150x5.0 26 HK$4,420.00 HK$3,000.0 HK$5,080.00 140x140x5.0 26.00 HK$4,420.00 HK$3,000.0 HK$5,080.00 120x120x5.0 26.20 HK$4,454.00 HK$3,000.0 HK$5,096.00 100x100x4.0 32.80 HK$5,576.00 HK$3,000.0 HK$5,624.00 90x90x3.6 36.3 HK$6,171.00 HK$3,000.0 HK$5,904.00 80x80x3.0 36.5 HK$6,205.00 HK$3,000.0 HK$5,920.00 70x70x3.0 36.6 HK$6,222.00 HK$3,000.0 HK$5,928.00 60x60x3.0 43.9 HK$7,463.00 HK$3,000.0 HK$6,512.00 50x50x3.0 44.1 HK$7,497.00 HK$3,000.0 HK$6,528.00 40x40x3.0 44.6 HK$7,582.00 HK$3,000.0 HK$6,568.00
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Guidelines on Long First Maintenance Period CorrosionProtection Systems
CTW/MKL/IL/
Issue No./Revision No. : 1/1 Issue/Revision Date : January 2009
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RHS
SectionSurface
Area /tonneCost Comparison of Different Protection ($ / ton of section)
mm (m2 /ton) Painting Galvanize only Gal+Painting
500x300x8.0 16.1 HK$2,737.00 HK$3,000.0 HK$4,288.00 450x250x8.0 16.2 HK$2,754.00 HK$3,000.0 HK$4,296.00 400x200x8.0 16.2 HK$2,754.00 HK$3,000.0 HK$4,296.00 300x200x6.3 20.5 HK$3,485.00 HK$3,000.0 HK$4,640.00 300x100x8.0 16.3 HK$2,771.00 HK$3,000.0 HK$4,304.00 250x150x5.0 25.9 HK$4,403.00 HK$3,000.0 HK$5,072.00 250x100x10 13.2 HK$2,244.00 HK$3,000.0 HK$4,056.00 200x150x8.0 16.4 HK$2,788.00 HK$3,000.0 HK$4,312.00 200x120x5.0 26 HK$4,420.00 HK$3,000.0 HK$5,080.00 200x100x5.0 26 HK$4,420.00 HK$3,000.0 HK$5,080.00 160x80x4.0 32.6 HK$5,542.00 HK$3,000.0 HK$5,608.00 150x100x5.0 26.2 HK$4,454.00 HK$3,000.0 HK$5,096.00 120x80x5.0 26.3 HK$4,471.00 HK$3,000.0 HK$5,104.00 120x60x3.6 36.2 HK$6,154.00 HK$3,000.0 HK$5,896.00 100x60x3.6 36.5 HK$6,205.00 HK$3,000.0 HK$5,920.00 100x50x3.0 43.5 HK$7,395.00 HK$3,000.0 HK$6,480.00 90x50x3.6 41.3 HK$7,021.00 HK$3,000.0 HK$6,304.00 80x40x3.2 44.1 HK$7,497.00 HK$3,000.0 HK$6,528.00 60x40x3.0 42.1 HK$7,157.00 HK$3,000.0 HK$6,368.00
Cost of painting > 110% of Cost of gal + painting